The 160z was too big for my hands, and I can't tie those particular models. Would a 140z from the same modell fit my hands better, or are they the exact same size inside?

In my experience, it's really based on the size, but the brand really. I have the Everlast Prime boxing gloves that are 16 oz. that are too big for my hands but my Top King gloves (a Thai brand) is also 16 oz. and fit my hands perfectly. So to me different brands I believe have different sizes that fit to different people.

If you have one where you live, go to a Title Boxing Club and try their gloves and see if it makes a difference size-wise._________________"When I have listened to my mistakes, I have grown." ~Bruce Lee